The samples were dissolved with ferric chloride solution, and the metallic iron was oxidized to ferrous chloride. After filtration and separation, the acidified filtrate was titrated by potassium dichromate standard solution using sodium diphenylamine sulfonate as indicator, realizing the determination of metallic iron in reduction products of titanium fine powder. The results showed that the optimal experimental conditions were as follows: the sample granularity was less than 0. 125 mm; the concentration and dosage of ferric chloride solution were 10 g/L and 100 mL, respectively; the electromagnetic stirring time was 60 min. The accuracy of method was tested using HgCl2 analysis and mineral phase detection. The F test and t test results indicated that this method had no significant difference from HgCl2 method. Meanwhile, the comparison of X-ray diffraction and metallograph for sample before and after leaching further proved that there was no metallic iron phase in filter residue and the iron was fully leached. This method was applied to the determination of reduction product samples of titanium fine powder, and the relative standard deviation (RSD) of results was smaller than 2 ％.%试样用三氯化铁溶液溶解,金属铁被氧化为二氯化铁,过滤分离,滤液酸化后以二苯铵磺酸钠为指示剂,用重铬酸钾标准溶液滴定,实现了钛精粉还原产物中金属铁含量的测定.结果表明,试样粒度在0.125 mm以下时,FeCl3溶液浓度和用量分别为10 g/L和100 mL,采用电磁搅拌60 min为最佳的实验条件.分别用HgCl2分析法、矿相法对方法正确度进行检测,其中F检验和t检验判定此法与HgCl2法无显著性差异,同时,浸出前后试样的X射线衍射图谱对照和金相照片对比进一步证明滤渣中没有金属铁相,铁浸出完全.方法用于测定钛精粉还原产物样品,结果的相对标准偏差小于2%.
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